Publications

In recent decades governments and society have been making increasing efforts to address and mitigate climate change by reducing emissions and decarbonising energy generation. Ireland has invested greatly in renewable electricity installing 4 GW of wind capacity since 2002 and has set assertive energy targets such as the aim to reduce overall emissions by 51% by 2030. Nonetheless considerable acceleration is needed in the decarbonisation of the country’s energy sector. This paper investigates the potential role hydrogen can play in Ireland’s energy transition proposing hydrogen as an energy vector and storage medium that may help the country achieve its targets and reduce greenhouse gas emissions. Through literature review research and from industry insights the current state of the Irish energy sector is analysed and recommendations are made as to how where and when hydrogen can be integrated into the decarbonisation of Ireland’s electricity heating and transport. It is concluded that; with significant effort from the government policymakers industry and organisations; the effective deployment of hydrogen technologies in Ireland could avoid up to 6.1 MtCO2eq of emissions annually reflecting a trend observed in many other developed countries in which hydrogen plays an important part in the path to a low-carbon future. Prospective roles for hydrogen in Ireland include renewable energy storage and grid balancing through the deployment of Power-to-Gas systems a replacement for fossil natural gas in the gas grid for backup electricity production as well as industry and heating requirements and the use of hydrogen as a fuel for heavy transport.

In this paper we show for the first time the feasibility of ammonia exhaust gas reforming as a strategy for hydrogen production used in transportation. The application of the reforming process and the impact of the product on diesel combustion and emissions were evaluated. The research was started with an initial study of ammonia autothermal reforming (NH3 e ATR) that combined selective oxidation of ammonia (into nitrogen and water) and ammonia thermal decomposition over a ruthenium catalyst using air as the oxygen source. The air was later replaced by real diesel engine exhaust gas to provide the oxygen needed for the exothermic reactions to raise the temperature and promote the NH3 decomposition. The main parameters varied in the reforming experiments are O2/NH3 ratios NH3 concentration in feed gas and gas e hourly e space e velocity (GHSV). The O2/NH3 ratio and NH3 concentration were the key factors that dominated both the hydrogen production and the reforming process efficiencies: by applying an O2/NH3 ratio ranged from 0.04 to 0.175 2.5e3.2 l/min of gaseous H2 production was achieved using a fixed NH3 feed flow of 3 l/min. The reforming reactor products at different concentrations (H2 and unconverted NH3) were then added into a diesel engine intake. The addition of considerably small amount of carbon e free reformate i.e. represented by 5% of primary diesel replacement reduced quite effectively the engine carbon emissions including CO2 CO and total hydrocarbons.

This article presents findings from a representative survey fielded through the Norwegian Citizen Panel examining public perceptions of hydrogen fuel and its different production methods. Although several countries including Norway have strategies to increase the production of hydrogen fuel our results indicate that hydrogen as an energy carrier and its different production methods are still unknown to a large part of the public. A common misunderstanding seems to be confusing ‘hydrogen fuel’ in general with environmentally friendly ‘green hydrogen’. Results from a survey experiment (N = 1906) show that production method is important for public acceptance. On a five-point acceptance scale respondents score on average 3.9 for ‘green’ hydrogen which is produced from renewable energy sources. The level of acceptance is significantly lower for ‘blue’ (3.2) and ‘grey’ (2.3) hydrogen when respondents are informed that these are produced from coal oil or natural gas. Public support for hydrogen fuel in general as well as the different production methods is also related to their level of worry about climate change gender and political affiliation. Widespread misunderstandings regarding ‘green’ hydrogen production could potentially fuel public resistance as new ‘blue’ or ‘grey’ projects develop. Our results indicate a need for clearer communication from the government and developers regarding production methods to avoid distrust and potential public backfire.

Alternatives to cope with the challenges of high shares of renewable electricity in power systems have been addressed from different approaches such as energy storage and low-carbon technologies. However no model has previously considered integrating these technologies under stability requirements and different climate conditions. In this study we include this approach to analyse the role of new technologies to decarbonise the power system. The Spanish power system is modelled to provide insights for future applications in other regions. After including storage and low-carbon technologies (currently available and under development) batteries and hydrogen fuel cells have low penetration and the derived emission reduction is negligible in all scenarios. Compressed air storage would have a limited role in the short term but its performance improves in the long term. Flexible generation technologies based on hydrogen turbines and long-duration storage would allow the greatest decarbonisation providing stability and covering up to 11–14 % of demand in the short and long term. The hydrogen storage requirement is equivalent to 18 days of average demand (well below the theoretical storage potential in the region). When these solutions are considered decarbonising the electricity system (achieving Paris targets) is possible without a significant increase in system costs (< € 114/MWh).

This paper reviews the relationship between the production of steel and the environment as it stands today. It deals with raw material issues (availability scarcity) energy resources and generation of by-products i.e. the circular economy the anthropogenic iron mine and the energy transition. The paper also deals with emissions to air (dust Particulate Matter heavy metals Persistant Organics Pollutants) water and soil i.e. with toxicity ecotoxicity epidemiology and health issues but also greenhouse gas emissions i.e. climate change. The loss of biodiversity is also mentioned. All these topics are analyzed with historical hindsight and the present understanding of their physics and chemistry is discussed stressing areas where knowledge is still lacking. In the face of all these issues technological solutions were sought to alleviate their effects: many areas are presently satisfactorily handled (the circular economy—a historical’ practice in the case of steel energy conservation air/water/soil emissions) and in line with present environmental regulations; on the other hand there are important hanging issues such as the generation of mine tailings (and tailings dam failures) the emissions of greenhouse gases (the steel industry plans to become carbon-neutral by 2050 at least in the EU) and the emission of fine PM which WHO correlates with premature deaths. Moreover present regulatory levels of emissions will necessarily become much stricter.

Hydrogen has set high hopes for decarbonization due to its flexibility and ability to decarbonize sectors of the economy where direct electrification appears unviable. Broad hydrogen policies have therefore started to emerge. Nevertheless it is still a rather niche technology not integrated or adopted at scale and not regulated through particular policy provisions. The involved stakeholders are thus still rushing to set the agenda over the issue. All this plays out publicly and shapes the public discourse. This paper explores how the composition of stakeholders their positions and the overall discourse structure have developed and accompanied the political agenda-setting in the early public debate on hydrogen in Germany. We use discourse network analysis of media where stakeholders' claims-making is documented and their positions can be tracked over time. The public discourse on hydrogen in Germany shows the expected evolution of statements in connection with the two milestones chosen for the analyses the initiation of the Gas 2030 Dialogue and the publication of the National Hydrogen Strategy. Interestingly the discourse was comparatively feeble in the immediate aftermath of the respective milestones but intensified in a consolidation phase around half a year later. Sequencing the discourse and contextualizing its content relative to political societal and economic conditions in a diachronic way is essential because it helps to avoid misinterpreting the development of stakeholders' standpoints as conflict-driven rather than mere repositioning. Thus we observed no discourse “polarization” even though potentially polarizing issues were already present in the debate.

A numerical study was conducted to investigate the effects of hydrogen and scavenging air temperature (SAT) on the combustion and emission characteristics of a 2-stroke heavy-duty dual-fuel (DF) marine engine at full load. The engine had a 700 mm bore fuelled with hydrogen–methane (H2-CH4) mixtures. Three-dimensional simulations of the combustion and emission formation inside the engine cylinder with various H2 contents in the H2-CH4 mixture were performed. ANSYS FLUENT simulation software was used to analyse the engine performance in-cylinder pressure temperature and emission characteristics. The CFD models were validated against the measured data recorded from the engine experiments. The results showed that an increase in the in-cylinder peak pressure increased the engine power when the H2 content in the H2-CH4 mixture increased. Notably CO2 and soot emissions decreased (up to more than 65%) when the H2 content in the gaseous mixture increased to 50%. Specific NO emissions in the DF modes were lower than that of the diesel mode when the H2 content in the gaseous mixture was lower than 40%. However they increased compared to the diesel mode when the H2 content continued to increase. This limits the H2 amount that should be used in a gaseous mixture creating NO emissions. The results also showed that the SAT cooling method can further reduce emission problems while enhancing engine power. In particular reducing the SAT to 28 ◦C in the gaseous mixture with 10% H2 ensured that the DF mode emitted the lowest NO emissions compared to the diesel mode. This reduced NO emissions by 37.92% compared to the measured NO emissions of the research engine (a Tier II marine engine). This study successfully analysed the benefits of using an H2-CH4 mixture as the primary fuel and the SAT cooling method in a 2-stroke ME-GI heavy-duty marine engine.

The Government is committed to developing the UK’s low carbon hydrogen economy: hydrogen is considered critical to delivering energy security and our decarbonisation targets and presents a significant growth opportunity. It can play a pivotal role in our transition to a future based on renewable and nuclear energy while ensuring that natural gas used during this transition is from reliable sources including our own North Sea production and can provide clean energy for use in industry power transport and potentially home heating. In the UK Hydrogen Strategy we included the commitment to regularly summarise our policy development to keep industry apprised. Since publication of the Hydrogen Strategy we have doubled our low carbon hydrogen production capacity ambition to up to 10GW by 2030 (with at least half from electrolytic hydrogen) in the British Energy Security Strategy provided greater clarity to investors through the Hydrogen Investment Package and made substantial policy and funding strides across the hydrogen value chain. We summarised these ambitions commitments and actions in the first Hydrogen Strategy update to the market in July 2022. This was published alongside other key elements of our policy support which also included the launch of the first Electrolytic Hydrogen Allocation Round – offering joint Net Zero Hydrogen Fund (NZHF) and Hydrogen Production Business Model (HPBM) support – and our Hydrogen Sector Development Action Plan and the appointment of a UK Hydrogen Champion. Hydrogen is closely integrated into Government’s wider policy development on energy security and the energy transition both domestically and internationally with hydrogen policy previously announced through the Net Zero Strategy and the Breakthrough Agenda at COP26. This December 2022 Hydrogen Strategy update to the market summarises the extensive activity across Government since July to develop new hydrogen policy at pace and to design and deliver funding support. This includes announcements on shortlisted hydrogen projects in the Cluster Sequencing Process the launch of a consultation on hydrogen transport and storage (T&S) infrastructure the publication of the HPBM Heads of Terms and an update on the ongoing first Electrolytic Hydrogen Allocation Round. The hydrogen policy development presented here underlines the Government’s approach to promote every aspect of the UK hydrogen economy in collaboration with industry investors and international partners to create a strong globally competitive UK hydrogen sector.

Today with the increasing transition to electric vehicles (EVs) the design of highly energy-efficient vehicle architectures has taken precedence for many car manufacturers. To this end the energy consumption and recovery rates of different powertrain vehicle architectures need to be investigated comprehensively. In this study six different powertrain architectures—four independent in-wheel motors with regenerative electronic stability control (RESC) and without an RESC one-stage gear (1G) transmission two-stage gear (2G) transmission continuously variable transmission (CVT) and downsized electric motor with CVT—were mathematically modeled and analyzed under real road conditions using nonlinear models of an autonomous hydrogen fuel-cell electric vehicle (HFCEV). The aims of this paper were twofold: first to compare the energy consumption performance of powertrain architectures by analyzing the effects of the regenerative electronic stability control (RESC) system and secondly to investigate the usability of a downsized electrical motor for an HFCEV. For this purpose all the numerical simulations were conducted for the well-known FTP75 and NEDC urban drive cycles. The obtained results demonstrate that the minimum energy consumption can be achieved by a 2G-based powertrain using the same motor; however when an RESC system is used the energy recovery/consumption rate can be increased. Moreover the results of the article show that it is possible to use a downsized electric motor due to the CVT and this powertrain significantly reduces the energy consumption of the HFCEV as compared to all the other systems. The results of this paper present highly significant implications for automotive manufacturers for designing and developing a cleaner electrical vehicle energy consumption and recovery system.

The intermittent nature of renewable energy resources such as wind and solar causes the energy supply to be less predictable leading to possible mismatches in the power network. To this end hydrogen production and storage can provide a solution by increasing flexibility within the system. Stored hydrogen as compressed gas can either be converted back to electricity or it can be used as feed-stock for industry heating for built environment and as fuel for vehicles. This research is the first to examine optimal strategies for operating integrated energy systems consisting of renewable energy production and hydrogen storage with direct gas-based use-cases for hydrogen. Using Markov decision process theory we construct optimal policies for day-to-day decisions on how much energy to store as hydrogen or buy from or sell to the electricity market and on how much hydrogen to sell for use as gas. We pay special emphasis to practical settings such as contractually binding power purchase agreements varying electricity prices different distribution channels green hydrogen offtake agreements and hydrogen market price uncertainties. Extensive experiments and analysis are performed in the context of Northern Netherlands where Europe’s first Hydrogen Valley is being formed. Results show that gains in operational revenues of up to 51% are possible by introducing hydrogen storage units and competitive hydrogen market-prices. This amounts to a e126000 increase in revenues per turbine per year for a 4.5 MW wind turbine. Moreover our results indicate that hydrogen offtake agreements will be crucial in keeping the energy transition on track.